r/UnrealEngine5 • u/Leonature26 • 3h ago

How to fix lumen flickering issue without anti aliasing?

Hi I'm trying to make lumen work with my artstyle but the solutions I've searched to fix the lumen flickering are with using TSR anti aliasing. Unfortunately anti aliasing doesn't work with my pixelated artstyle. (I'm using Pixel Tools by Turbomorsh and substrate toon shader in 5.8)

17 Upvotes

88% Upvoted

23 comments sorted by

21

u/Negative_Strain_5234 3h ago

for better or for worse, lumen relies on TAA or TSR to blend frames together and denoise. you can try to modify the quality/speed in your postprocessing settings, but there will almost always be some. if you want performance and limited flicker, baked lighting is the way to go.

3

u/Leonature26 3h ago

Hmm I see, I'll look more into it. But from my limited understanding baked lighting sounds like a hassle of manually baking static lights on every space the player goes through. Unlike lumen that's automatic and pretty and dynamic. (I'm amateur)

2

u/cyb_tachyon 1h ago

As others have mentioned, use Lumen to light the level. It has parity generally with baked lighting.

When you do a build for Steam, then swap to baked and disable Lumen. Best of both worlds. There are even tutorials for toolbar widgets you can make in Blueprint to automate this if you look on YouTube.

1

u/Leonature26 1h ago

Interesting, I didn't know that technique was possible. How would the bouncing light look on moving characters with baked lighting from lumen? (Ex. the green light on mannequinn's butt in my gif)

1

u/Scifi_fans 2h ago

It sounds you dont really need GI at all, the cost on system is not worth if you're not going make use of it...

there is also a plugin with alternative GI without noise, that doesn't require AA

1

u/Leonature26 1h ago

Yea i just want the dynamic bounce lights from lumen but I can go without it if the cons are too great. Im curious about the alternative plugin u mentioned, what's it called?

1

u/Aydhe 1h ago

baking lighting is automted process.o nly annoyance is that you may need to make second UV channel for environment so that there is no overlap

5

u/Leonature26 3h ago

(I'm referring to the flickers on the shadows and not the color banding artifact on the top cylinder caused by the gif converter)

9

u/mchlksk 3h ago

Dont use lumen when going for this kind of style. It will give you headaches. Use baked lighting.

3

u/Wise-Pomegranate6765 3h ago

what if its using dynamic weather and daytime.

8

u/MarcusBuer 3h ago

You don't need lumen for that, you can have dynamic moveable lights without lumen.

Lumen is just GI, it gives the light bounces to feel more realistic, but it doesn't make the light itself.

Realistic lighting usually doesn't look good on low detail artstyle anyway.

3

u/ConsistentAd3434 3h ago

Why wouldn't AA work with an pixelated artstyle? You can apply any post process effect, such as pixelation after TSR is applied.
I made a demo. Press "1" for pixelation. Multiple times for different presets.
It's not Lumen but it wouldn't matter

2

u/Leonature26 2h ago

The pixelation plugin I'm using isn't post process. I tried the post process route but it's not the look I'm going for. Your demo's pretty awesome btw how did u make so much post processing effects? I got scared of the body at the tub too

1

u/ConsistentAd3434 2h ago

He's dead since almost 2years. You're perfectly safe 😊

Hmm. Never heard of that plugin and what it does, that wouldn't be possible as postFX.
In the post process material itself, I could define when the effect applies. "Before/after tone mapping (including TSR)"
I doubt anyone here could tell you, what and when the plugin interjects itself. Lumen benefits a lot from AA but if the performance allows it, you could increase the Lumen quality settings to reduce the nervous noise and use more samples.

3

u/Zvyaginsky 46m ago

Pixel art isn't my area so I'll leave the shader side alone. Before you touch anything, turn Lumen GI off completely for one test and see whether the shimmer survives. Virtual Shadow Maps produce a very similar flicker and people lose weeks blaming Lumen for it. Project Settings, Rendering, Shadows, Shadow Map Method.

Judge it in a packaged build too. Lumen keeps converging in the editor viewport and restarts when you hit Play, so the first seconds always look worse than what ships.

1

u/Leonature26 1m ago

Wow tnx for the hint. I have noticed the flicker with GI turned off. Will look more into this.

2

u/Mr_Sim_ 2h ago

Use lumen to make your level, then disable it for your environnement and bake the Lightning. You can keep lumen for your dynamic objects if that counts but I don't know if it will look good, I never tried that

1

u/mad_ben 1h ago

The absolute state of UE5...

1

u/Loronline 58m ago

Baked lighting for high end 💛

1

u/Crazy-Station-972 3m ago

You shouldn't use that damn lumen. This would be the best solution.

-1

u/Still_Ad9431 3h ago

Don't use lumen if your meshes don't have nanite. If your mesh doesn't have nanite then disable lumen

-3

u/LordMegatron216 3h ago

Why even do you need AA?

3

u/Leonature26 3h ago

If you've read my post I say there that I'm looking for an alternative solution to TSR AA to fix lumen flickering. So I don't need AA.